nixos: k3: add terminfo for urxvt
nixos: k3: add terminfo for urxvt

This is for when we SSH into this machine. It probably has something to
do with the urxvt binary running on the remote machine requesting
terminfo information from the server. Without this terminfo package, our
urxvt from the client side gets wonky.

listx/syscfg,listx/syscfg,listx/syscfg,listx/syscfg,listx/syscfg